1. Technical Field
This invention relates generally to document production apparatus such as copiers and/or printers, and more particularly to a diagnostic and administrative device to provide a user, such as an operator or repair technician, with a quick and accurate system for defining and solving equipment problems.
2. Background Art
Document production apparatus such as for example electrophotographic copiers and printers commonly include systems for monitoring various process parameters such as paper feed timing, temperatures, availability of consumables, etc. When a parameter exceeds its set point, the apparatus may be shut down for repairs If the parameter is not critical to continued operation, the apparatus may be allowed to continue operations while an operator is alerted to the need for maintenance or other action.
Document production apparatus is available wherein the apparatus itself maintains a record of the number of occurrences of serious and less serious shutdowns. The apparatus may even trigger a call for service when a predetermined number of these less serious shutdowns have been recorded However, there is no system available for document production apparatus wherein the user is provided with a quick and accurate method for defining and solving equipment problems.
Generally, a diagnosis and repair process entails defining the problem, often in the form of a symptom or symptoms being experienced in the equipment. Normally, the symptom is defined through observation, user interview, past history, and machine problem logs. The symptom is often labeled using jargon common to the type of equipment under test. For example, symptoms in electrophotographic document production apparatus may include "smears," "jams," "supplies empty," etc.
After the symptom has been classified, the repair person either through expert knowledge or through documentation, develops a series of suspected causes to the symptom. These suspected causes are then ranked in order of probability to cause the symptom.
The repair person then begins to eliminate each possible cause by performing some type of check-out procedure. If a check-out procedure shows a failure, a repair is effected. The success of the repair in eliminating the symptom is determined. If the symptom is eliminated, the process is considered to be successfully completed. If the symptom persists, the repair person must continue checking other suspected causes until the original problem is repaired.
While the procedure is generally performed to check out only a single cause to the symptom or symptoms, information derived from specific check-outs to help eliminate one suspect cause may be used to eliminate another suspect cause. For example, if a symptom might be caused by a motor failure or by the lack of electrical power to the motor, a determination that the motor runs would also rule out the possibility that there is no power to the motor. This determination by induction is invaluable in creating an efficient diagnostic process by eliminating the need to run many checks.
Automatic diagnostic procedures are known, but currently known diagnostic processes suffer from a lack of accuracy and timeliness of the information. It is also found that no matter how good a diagnostic system is, it will never be 100% correct. Conventional automated diagnostic systems which do not embrace an opportunity for manual intervention by a trained user are severely handicapped in this regard.